The .21 Off Road Ninja seems to be very fast and smooth on the track. Taking the 7mm restrictor out helped performance a lot. So far the people that see it run want one.

Yep (at least on this side of the ocean)... and isn't BS of recalls and other nightmares... actually have one here ready to be installed on my new 4-R. Got the long manifold (there's two versions: Long and short), the most shocking is the pipe, is the same for on-road and off-road

Photos of it in very short time!.

Anyone else ran the .21 Ninja onroad?

Mike Swauger and Darin Ishitani both are using the Ninja MR 21 R01 in the Las Vegas Grand Prix and both are ballistic Fast and according to both of them they are both Bone stock (?)

Sounds great.

All team drivers tell they run box stock engine, old story LOL

Gonna check it... if everything goes fine, Sunday my new MRX4 will be finished and I could break-in the R01 and we'll see how performs that puppy, next weekend there's a national here and is expected to see some of those engines showing some muscle.

Here are some photos of the MR-R01 I got yesterday.

Some about it:

1. Looks impressive, the packaging too is at another level.
2. Has a 9mm carb and a 8.5mm restrictor inserted into it (removing it is a PITA). Looks like the ones from Sirio carbs too, their diameter is laser etched into the side, so you will not need to figure which restrictor (if you have installed one) is.
3. Look at the crankshaft. Another shot of it.
4. Views of the sleeve (Exhaust port), another view (side ports) and another (Boost port).
5. Views of the piston (Domed and concave). Another view, this time of the side of the conrod, has a very sharp edge on the lower side and has the same channel of the R5 & R6 Nova conrods.
6. The crankcase. Their machining seems more delicate and refined as Nova ones.
7. Views of the pipe. Another view note that exhaust stinger points to the ground rather than being at 90º. The manifold is conical and is the long version (MR14003). The pipe is the same of Off-Road and On-Road (part no MR15001 - EFRA 2053).

The wait for testing it will be hard, but need to finish my car to test that s*cker. More news about it in few days (I suppose...).

nice picks, looks like its got some ammo

The Ninja perfomance and Sirio PR Pro perfomance are same?Which is better on the same track in your opinion?

Sorry, haven't tested the Ninja yet, and the unique Sirio PR21 I've had was about 3 years ago (the first PR21 - the one with the black head). Aren't comparable (well could be compared but wouldn't be fair for the ancient PR21...).

Corse-R: In picture 1473 I noticed there is an APS "stamp" and what looks like some scratches on the the counterweight. Any thoughts on that?

Saw them when I dismantled the engine for a revision and cleaning (and of course, a photo session... ). Examined them with a 10x loupe and are scratches of the machining (look at them and you'll that are circular - done them with a rotating bit). Are inofensive, just the looks.

Thanks for the info! It will help me from getting alarmed if its like that on the T01s.

and blowing rods